1. Field of the Invention
This invention relates generally to apparatus for displaying visible light to a viewer while retarding a displayer's perception of the displayed light. More particularly, but not by way of limitation, this invention relates to apparatus for displaying information which is placed on the line of sight between the viewer and the displayer.
2. Description of the Prior Art (Prior Art Statement)
The following statement is intended to be a Prior Art Statement in compliance with the guidance and requirements of 37 C.F.R. Sections 1.56, 1.97 and 1.98.
U.S. Pat. No. 2,352,644 issued to Linderman, Jr., et al. discloses an apparatus for estimating ranges which proposes right triangular prisms joined along their hypotenuse sides and containing an image applied to the top surface of the resultant cube.
U.S. Pat. No. 2,860,544 issued to Kahn proposes a viewing device having a vertical display area physically offset from the viewer's line of sight and further having mirrors to display material to the viewer.
U.S. Pat. No. 2,920,134 issued to Dresser discloses a cueboard and spot projection for electronic picture taking. This includes a cue indicator which operates during "blind" periods of a picture tube thereby permitting the cued material to appear visible to a direct viewer thereof through persistence of vision, but does not permit it to be visible to the camera containing the picture tube.
U.S. Pat. No. 2,926,559 issued to Oppenheimer discloses a prompting apparatus for cameras which includes reflecting means for reflecting material to be read by a reader onto the line between the reader and the lens of the camera.
U.S. Pat. No. 3,060,308 issued to Fortuna discloses an illuminated optical device. In particular this device includes spectacles which have light sources disposed above the lenses.
U.S. Pat. No. 3,245,315 issued to Marks et al. discloses an electro-optic responsive flashblindness controlling device having crystal layers between transparent conductive coatings and also having polarizers associated with the crystal layers. These elements are incorporated into a pair of glasses which includes a photocell and power supply for activating the crystal layers to become opaque to prevent flashblindness.
U.S. Pat. No. 3,712,714 issued to Uyeda et al. discloses an information display for a diver's face mask. This is proposed to include an information display means mounted to the mask out of the diver's normal line of sight. The display means is reflected by appropriate means to be visible to the diver upon the shifting of his eyes to the proper location.
U.S. Pat. No. 3,873,804 issued to Gordon proposes a welding helmet with eye piece control having a liquid crystal member incorporated into the protective welding lens. The liquid crystal member is activated by electrical energy to control the opacity of the liquid crystal as a result of the welding activity.
U.S. Pat. No. 4,021,935 issued to Witt discloses a flight training hood which has a liquid crystal viewing lens whose opacity is controllable to occlude the wearer's vision.
U.S. Pat. No. 4,039,803 issued to Harsch discloses an electro-optic welding helmet lens assembly which has a liquid crystal light shutter responsive to infra-red and visible light energy.
U.S. Pat. No. 4,071,912 issued to Budmiger discloses a light filter for a welder's mask having ceramic crystals or fluid crystals between transparent electrodes. The opacity of the welder's mask is triggered by an activator circuit responsive to sound or light.
As shown by the above-mentioned disclosures, there is a need for an apparatus which can respond to certain stimuli to occlude unwanted light from the user's eyes. However, there is the additional need to have such a responsive apparatus which occludes certain light for certain purposes yet which does not substantially adversely affect normal vision. There is also the need for data display glasses which provide visible information to a viewer from the eye region of the displayer without substantially adversely affecting the displayer's vision and without displaying the information to the displayer. An additional need is to provide a direct source of light along the line of sight between the viewer and the subject to be examined. Still further there is the need for variably controlled sunglasses. Also there is a need for security panels which provide uni-directional vision therethrough.
The previous disclosures, however, do not propose apparatus which meet these needs. These references fail to indicate apparatus which display information or provide illumination directly along the line of sight between the apparatus users and viewers. Still further the prior references fail to show the combination of frequency responsive occluding elements with frequency responsive illumination elements. Therefore, Applicant believes that no previously disclosed device which is known to him indicates, either singly or in combination, the present invention.